1. Field of the Invention
This invention relates to apparatus for making and breaking electrical circuits, and particularly to a readily assembled, space efficient branch circuit breaker automatically operable in response to current overloads.
2. Description of the Prior Art and Summary of the Invention
Molded case automatic circuit breakers which are removably mounted in electrical panelboards are commonly used to control branch circuits in residential and commercial applications. Representative circuit breakers are disclosed by U.S. Pat. Nos. 3,098,136, 3,109,907 and 3,443,258 which are assigned to the same assignee as the instant invention and are hereby incorporated by reference. The '907 patent discloses a two pole circuit breaker having separate operating mechanisms which control independent branch circuits and which occupy substantially the same space as the single pole mechanism disclosed in either of the other two patents. In accordance with the instant invention, there is provided a two pole circuit breaker having the poles in side by side or stacked relationship as opposed to end to end relationship as in the '907 patent. A substantial reduction in width of each of the poles requires particular attention to component design to assure adequate mechanical strength and proper current carrying capacity while maintaining appropriate electrical clearances to enable the circuit breaker to operate properly.
An object of the present invention is to provide an improved circuit breaker which is of simple and economic construction.
A further object of the present invention is to facilitate automated assembly of the circuit breaker.
A further object of the present invention is to provide a side-by-side, stacked, two-pole circuit breaker having a width of substantially 3/8 inch per pole and overall enclosure width of approximately 3/4 inch.
A further object of the present invention is to provide an improved and economical bimetal assembly.
A further object of the present invention is to provide an improved multi-function trip lever.
A further object of the present invention is to provide an improved and more economical arc shield which is integral with the circuit breaker casing.
A further object of the present invention is to provide an improved movable contact blade requiring a minimum of scrap during formation of the blade.
A further object of the present invention is to provide a single jaw having two line side contacts connected thereto which allows two breaker poles to share a single jaw of the same polarity.
A further object of the present invention is to provide an improved low current magnetic trip assembly.
Further objects and features of the invention will be readily apparent to those skilled in the art from the following specification including the appended claims and the accompanying drawings of the invention in which: